arch/powerpc/boot/main.c

   1 /*
   2  * Copyright (C) Paul Mackerras 1997.
   3  *
   4  * Updates for PPC64 by Todd Inglett, Dave Engebretsen & Peter Bergner.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11 #include <stdarg.h>
  12 #include <stddef.h>
  13 #include "elf.h"
  14 #include "page.h"
  15 #include "string.h"
  16 #include "stdio.h"
  17 #include "ops.h"
  18 #include "gunzip_util.h"
  19 #include "flatdevtree.h"
  20 #include "reg.h"
  21
  22 static struct gunzip_state gzstate;
  23
  24 struct addr_range {
  25         void *addr;
  26         unsigned long size;
  27 };
  28
  29 #undef DEBUG
  30
  31 static struct addr_range prep_kernel(void)
  32 {
  33         char elfheader[256];
  34         void *vmlinuz_addr = _vmlinux_start;
  35         unsigned long vmlinuz_size = _vmlinux_end - _vmlinux_start;
  36         void *addr = 0;
  37         struct elf_info ei;
  38         int len;
  39
  40         /* gunzip the ELF header of the kernel */
  41         gunzip_start(&gzstate, vmlinuz_addr, vmlinuz_size);
  42         gunzip_exactly(&gzstate, elfheader, sizeof(elfheader));
  43
  44         if (!parse_elf64(elfheader, &ei) && !parse_elf32(elfheader, &ei))
  45                 fatal("Error: not a valid PPC32 or PPC64 ELF file!\n\r");
  46
  47         if (platform_ops.image_hdr)
  48                 platform_ops.image_hdr(elfheader);
  49
  50         /* We need to alloc the memsize: gzip will expand the kernel
  51          * text/data, then possible rubbish we don't care about. But
  52          * the kernel bss must be claimed (it will be zero'd by the
  53          * kernel itself)
  54          */
  55         printf("Allocating 0x%lx bytes for kernel ...\n\r", ei.memsize);
  56
  57         if (platform_ops.vmlinux_alloc) {
  58                 addr = platform_ops.vmlinux_alloc(ei.memsize);
  59         } else {
  60                 if ((unsigned long)_start < ei.memsize)
  61                         fatal("Insufficient memory for kernel at address 0!"
  62                                " (_start=%p)\n\r", _start);
  63         }
  64
  65         /* Finally, gunzip the kernel */
  66         printf("gunzipping (0x%p <- 0x%p:0x%p)...", addr,
  67                vmlinuz_addr, vmlinuz_addr+vmlinuz_size);
  68         /* discard up to the actual load data */
  69         gunzip_discard(&gzstate, ei.elfoffset - sizeof(elfheader));
  70         len = gunzip_finish(&gzstate, addr, ei.loadsize);
  71         if (len != ei.loadsize)
  72                 fatal("ran out of data!  only got 0x%x of 0x%lx bytes.\n\r",
  73                                 len, ei.loadsize);
  74         printf("done 0x%x bytes\n\r", len);
  75
  76         flush_cache(addr, ei.loadsize);
  77
  78         return (struct addr_range){addr, ei.memsize};
  79 }
  80
  81 static struct addr_range prep_initrd(struct addr_range vmlinux, void *chosen,
  82                                      unsigned long initrd_addr,
  83                                      unsigned long initrd_size)
  84 {
  85         /* If we have an image attached to us, it overrides anything
  86          * supplied by the loader. */
  87         if (_initrd_end > _initrd_start) {
  88                 printf("Attached initrd image at 0x%p-0x%p\n\r",
  89                        _initrd_start, _initrd_end);
  90                 initrd_addr = (unsigned long)_initrd_start;
  91                 initrd_size = _initrd_end - _initrd_start;
  92         } else if (initrd_size > 0) {
  93                 printf("Using loader supplied ramdisk at 0x%lx-0x%lx\n\r",
  94                        initrd_addr, initrd_addr + initrd_size);
  95         }
  96
  97         /* If there's no initrd at all, we're done */
  98         if (! initrd_size)
  99                 return (struct addr_range){0, 0};
 100
 101         /*
 102          * If the initrd is too low it will be clobbered when the
 103          * kernel relocates to its final location.  In this case,
 104          * allocate a safer place and move it.
 105          */
 106         if (initrd_addr < vmlinux.size) {
 107                 void *old_addr = (void *)initrd_addr;
 108
 109                 printf("Allocating 0x%lx bytes for initrd ...\n\r",
 110                        initrd_size);
 111                 initrd_addr = (unsigned long)malloc(initrd_size);
 112                 if (! initrd_addr)
 113                         fatal("Can't allocate memory for initial "
 114                                "ramdisk !\n\r");
 115                 printf("Relocating initrd 0x%lx <- 0x%p (0x%lx bytes)\n\r",
 116                        initrd_addr, old_addr, initrd_size);
 117                 memmove((void *)initrd_addr, old_addr, initrd_size);
 118         }
 119
 120         printf("initrd head: 0x%lx\n\r", *((unsigned long *)initrd_addr));
 121
 122         /* Tell the kernel initrd address via device tree */
 123         setprop_val(chosen, "linux,initrd-start", (u32)(initrd_addr));
 124         setprop_val(chosen, "linux,initrd-end", (u32)(initrd_addr+initrd_size));
 125
 126         return (struct addr_range){(void *)initrd_addr, initrd_size};
 127 }
 128
 129 /* A buffer that may be edited by tools operating on a zImage binary so as to
 130  * edit the command line passed to vmlinux (by setting /chosen/bootargs).
 131  * The buffer is put in it's own section so that tools may locate it easier.
 132  */
 133 static char cmdline[COMMAND_LINE_SIZE]
 134         __attribute__((__section__("__builtin_cmdline")));
 135
 136 static void prep_cmdline(void *chosen)
 137 {
 138         if (cmdline[0] == '\0')
 139                 getprop(chosen, "bootargs", cmdline, COMMAND_LINE_SIZE-1);
 140
 141         printf("\n\rLinux/PowerPC load: %s", cmdline);
 142         /* If possible, edit the command line */
 143         if (console_ops.edit_cmdline)
 144                 console_ops.edit_cmdline(cmdline, COMMAND_LINE_SIZE);
 145         printf("\n\r");
 146
 147         /* Put the command line back into the devtree for the kernel */
 148         setprop_str(chosen, "bootargs", cmdline);
 149 }
 150
 151 struct platform_ops platform_ops;
 152 struct dt_ops dt_ops;
 153 struct console_ops console_ops;
 154 struct loader_info loader_info;
 155
 156 void start(void)
 157 {
 158         struct addr_range vmlinux, initrd;
 159         kernel_entry_t kentry;
 160         unsigned long ft_addr = 0;
 161         void *chosen;
 162
 163         /* Do this first, because malloc() could clobber the loader's
 164          * command line.  Only use the loader command line if a
 165          * built-in command line wasn't set by an external tool */
 166         if ((loader_info.cmdline_len > 0) && (cmdline[0] == '\0'))
 167                 memmove(cmdline, loader_info.cmdline,
 168                         min(loader_info.cmdline_len, COMMAND_LINE_SIZE-1));
 169
 170         if (console_ops.open && (console_ops.open() < 0))
 171                 exit();
 172         if (platform_ops.fixups)
 173                 platform_ops.fixups();
 174
 175         printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r",
 176                _start, get_sp());
 177
 178         /* Ensure that the device tree has a /chosen node */
 179         chosen = finddevice("/chosen");
 180         if (!chosen)
 181                 chosen = create_node(NULL, "chosen");
 182
 183         vmlinux = prep_kernel();
 184         initrd = prep_initrd(vmlinux, chosen,
 185                              loader_info.initrd_addr, loader_info.initrd_size);
 186         prep_cmdline(chosen);
 187
 188         printf("Finalizing device tree...");
 189         if (dt_ops.finalize)
 190                 ft_addr = dt_ops.finalize();
 191         if (ft_addr)
 192                 printf(" flat tree at 0x%lx\n\r", ft_addr);
 193         else
 194                 printf(" using OF tree (promptr=%p)\n\r", loader_info.promptr);
 195
 196         if (console_ops.close)
 197                 console_ops.close();
 198
 199         kentry = (kernel_entry_t) vmlinux.addr;
 200         if (ft_addr)
 201                 kentry(ft_addr, 0, NULL);
 202         else
 203                 kentry((unsigned long)initrd.addr, initrd.size,
 204                        loader_info.promptr);
 205
 206         /* console closed so printf in fatal below may not work */
 207         fatal("Error: Linux kernel returned to zImage boot wrapper!\n\r");
 208 }